sharks and rays back in the north sea! - dutch shark …€¦ · reproductive biology of sharks is...

SHARKS AND RAYS BACK IN THE NORTH SEA!

Juvenile thornback rays© P

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ABOUT SHARKS AND RAYSImportant for the marine ecosystemLong before we humans walked this earth, beautiful sharks and rays were swimming in the world’s oceans. These apex predators have been at the top of the food chain for 450 million years, where they fulfil a vital role in the ecosystem of the oceans. They ‘maintain’ coral reefs, they ensure the ecological balance between species and they contribute to healthy populations of other animals by eating the weaker individuals. Largescale overfishing of sharks and rays affects the entire food chain and thus the health of the oceans.

Low reproductive capacitySharks and rays are characterized by a low reproductive capacity; many species are only sexually mature after more than 10 years. Most shark species develop their eggs inside the body of the female. Baby sharks are born fully developed. Most sharks have 1 to 20 pups per year. The reproductive biology of sharks is therefore more akin to that of marine mammals than fish. The Dutch North Sea is the habitat of several egg-laying shark species and rays: both the small-spotted catshark and the greater spotted dogfish or nursehound lay 18 to 20 eggs per year. The eggs take 7 to 10 months to hatch. The empty cases often wash up on beaches. Most Dutch bottom-dwelling rays lay eggs, from 20 to 140 eggs per year. Due to their low reproduction cycles, sharks and rays are vulnerable for overfishing, as the recovery of populations is very slow.

Marine Strategy Framework Directive (MSFD)In its policy for the implementation of the Marine Strategy Framework Directive (MSFD), the Dutch government has stated that in the Dutch part of the North Sea, the population size of vulnerable fish species such as sharks and rays must increase. Reversing a long-term negative trend in elasmobranch stocks must be facilitated by working on the recovery of habitats and by reducing bycatch.

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Threatened with extinctionWorldwide, a quarter of all sharks and rays are threatened with extinction (IUCN 2016, Red List of Threatened Species). In European waters, more than 30% of species are endangered. At the beginning of the 20th century, rays and skates were frequently found in the Dutch North Sea. Some species were intensively fished for consumption. When the Southern Sea was closed off in the thirties, an important juvenile habitat for sharks and rays was lost. Their numbers steadily decreased, until sharks and rays became rare in the southern North Sea after the Second World War. Due to the intensification of the fisheries in the North Sea from the fifties onwards and the use of heavier fishing gear, more and more areas have become accessible to fisheries. Because of this, these areas are no longer a refuge for sharks and rays.

Presently, only two species are regularly caught: the thornback ray and the spotted ray. The angel shark and the shagreen skate are probably extinct in the Dutch North Sea. Ten out of the twenty shark and ray species that still occur in the North Sea are on the IUCN Red List of threatened species. Most sharks and rays and their habitats are not protected.

Better protection neededThe habitats and nursery grounds for sharks and rays are insufficiently known and must be better charted and protected. Shallow breeding grounds such as coastal zones can become a refuge. Currently a joint project is being worked on with the Dutch fishing organizations that focuses on recognising catches, the survival of the caught animals and on monitoring the number of sharks and rays that are caught. Use is made of (automated) video image recognition and an innovative DNA method. With the information gathered from these methods and the estimated size of the populations, the effect of the fishing industry on the rays in the North Sea can be determined. This will enable us to advise on sustainable management of shark and ray species in the North Sea.

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SHARKS AND RAYS BACK IN THE NORTH SEA!ReintroductionThe numbers of sharks and rays have decreased to such an extent, or have even completely disappeared, that natural recovery of the population not seems feasible. The odds that they will return to the North Sea on their own accord is slim. Reintroducing sharks and rays which are (lo-cally) extirpated in the North Sea (such as the angelshark and the common skate) could possibly be the only way to reinstate these species in Dutch waters. Due to the slow reproductive capacity of sharks and rays, we have developed a long-term plan. Policy must also be adjusted to the long-term.

The pilot programme for reintroduction is divided into three phases, the reintroduction of the thornback ray is currently in phase three, the other species are in phase two..

There are several shark and ray species in the North Sea that are eligible for a reinforcement pro-gramme. The thornback ray (Raja clavata), still quite rare in Dutch waters, is already being bred in captivity. There are also other eligible species. Among other things, we consider which species are locally extinct and which species are suitable for breeding. For species that are not yet available through the aquaria, we will ask fishermen and (inter)national research institutes to supply eggs that they find in their fishing and research nets.

Phase 1: Setting up of aquariaIn cooperation with aquaria and zoos we have equipped Breeding Centre Blue Linked with tanks to breed thornback rays. Genetic research has shown that the cultures fit the profile of the population that is still present in the wild. We will also seek cooperation with foreign zoos and aquaria that have experience with breeding and caring for sharks and rays.

Phase 2: breeding programmeThornback eggs have been successfully reared at the Breeding centre Blue Linked in Utrecht. The next step will be to breed distinct species of viable sharks and rays from the collected eggs. In view of the successful breeding of rays in Dutch aquariums, we expect this to be a viable option. Both the breeding and the reintroduction programme will be set up in accordance with the IUCN Guidelines for Reintroductions and Other Conservation Translocations of the IUCN/SSC Re-Intro-duction Specialist Group (RSG) and will be made visible to the public. A week after the thornbacks have been tagged they will be returned to the former oyster pits in Yerseke to acclimatise in Ooster-scheldewater. Their well-being is checked there daily. After two weeks the animals can be released into the Oosterschelde.

Phase 3: pilot release programmeFrom the report ‘A habitat suitability analysis of the Oosterschelde and the Voordelta for the thorn-back ray (Raja clavata) in the Oosterschelde and the Voordelta’, it appears that these areas are potentially suitable as a habitat for the thornbacks. Taking into consideration assumptions and uncertainties, testing the conclusions through monitoring the released thornbacks with special tags (electronic data storage tags) is a necessary step in the development of knowledge about the thornbacks in the Oosterschelde and the Voordelta. This approach can also serve as an example for the habitat suitability analysis for other species of rays and sharks in this area. The first bred and tagged animals were released in the Oosterschelde in October 2017. The released rays are carefully monitored. For the (acoustic) tagging and monitoring of the rays, we collaborate with project part-ner Sportvisserij Nederland, which has been running a tag and release programme for sharks and rays in the Zeeland delta since 2012. The knowledge we have gained through this research and the reintroduction programme for sharks and rays can be used in worldwide reintroduction programs.

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Sustainable fisheriesThere is no targeted catch of sharks and rays in the Netherlands. The large problem, however, lies with the catch and bycatch of sharks and rays. The animals are mostly thrown back into the ocean, sometimes already dead. Dutch fishing policy for the coast and the inland waterways is aimed at a more sustainable fishing sector. Part of this policy is the ‘discard ban’: a ban on throwing fish back into the ocean. This ban does not include the species that are not allowed to be fished according to EU legislation, such as the endangered shark and ray species. These must still be released prompt-ly and unharmed.This exception does however not apply to all sharks and rays, and species that are not (yet) threatened can still be caught and landed. The discard ban is being introduced in phases, and it is possible to obtain an exemption for species with a high survival rate, such as sharks: they can easily survive being put back. More research is needed on rays, research that is currently taking place. An obligation for sharks to be released can aid the slow recovery of the species. We are committed to helping fishermen to achieve better recognition at species level and the importance of correct handling on board.

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Nursehound

Monique van de Water, World Wide Fund for Nature the Netherlands:“The common skate is a ray with a width of more than two meters. The tope shark can also grow to a length of 2 metres and was quite common in the North Sea in the past. I think it would be fantastic to see these magnificent, large marine creatures swimming in the North Sea again. The World Wide Fund for Nature works globally to protect sharks and rays. These animals are crucial for the health of our oceans.”

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Juvenile nursehound© P

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Protection and policyWith some exceptions (porbeagle shark, spiny dogfish and the common skate), many species in the North Sea are currently not sufficiently protected. A better legal protection at species level is necessary. The establishment of marine protected areas and fisheries regulations should be considered to achieve this.

Creating a support base for the protection of sharks and raysAt this moment in time there is no support base for the protection of sharks and rays. It is important to create awareness about their vulnerability and about the vital role they play in the ecosystem. We want to inform and involve the public more. For instance, through zoos and public aquaria that can inform their visitors about the project. Visitors can view the animals and learn more at both the breeding centre in Utrecht as well as at the oyster beds in Yerseke. The project has had a lot of media coverage and continues to do so, this contributes to creating more support and awareness. It is crucial for the protection of sharks and rays that we expand these activities.

Michaël Laterveer, Blue Linked:“Have the courage to pass on dreams. It would be fantastic to contribute to a healthy future for charismatic apex predators in their original and natural habitat; the coastal zone of the North Sea. As iconic predators, sharks and rays are the ultimate proof of a resilient ecosystem.”

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Sharks and rays in the North SeaNine different species of sharks occur in the North Sea. Until the seventies of the previous century, the spiny dogfish was the most common shark in the North Sea. International organizations now consider this an endangered species. The current population is only around 20% of the population of some decades ago. This species has a long reproduction period and adult females often school together. Catching such a school of females, often as bycatch, is disastrous for the species.

There are nine species of skates and rays in the North Sea. The thornback ray is not the most abundant species in the North Sea, but it is most frequently caught as a bycatch in the bottom trawl fisheries. Female thornback rays can reach a length of up to 120 cm and only mature at the age of nine years. Male thornback rays can grow up to 100 cm and are mature at eight years of age. The thornback ray is bottom dwelling and feeds on crustaceans and small fish. Most thornback rays remain close to their breeding ground. The flapper skate is the largest skate in the North Sea. They can grow up to 250 cm and weigh up to 100 kg. At the end of the 19th century, the Dutch fleet actively fished for common skates, but now this skate species has disappeared from the Dutch part of the North Sea.

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Starry smooth-hound© P

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Georgina Wiersma, Dutch Shark Society:“Globally, shark and ray populations have strongly decreased. I have had the privilege of meeting many of these animals in their natural habitat. It would be fantastic if that would be possible in our own North Sea because populations have recovered! It is my passion to show their beauty and importance for the ecosystem of our North Sea and the Zeeland delta. One only loves what one knows!”

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PLAN SHARKS AND RAYS BACK IN THE NORTH SEA!ObjectiveA North Sea with a recovered ecosystem, with healthy populations of sharks and rays. This objective must be achieved in 2030.

StrategyIncreasing the numbers and species of sharks and rays by:1. Safeguarding present shark and ray populations by limiting (by)catches.2. Breeding and releasing juveniles of endangered and (locally) extinct shark and ray species.3. Creating safe habitats for sharks and rays in which (by)catch is prevented as much as possible.

Intended results:• Increased population numbers of sharks and rays in 2030.• Protected status of currently known most important habitats and breeding grounds of sharks

and rays.• Sharks and rays will occur once again in at least one Natura 2000 area and their protection will

be well safeguarded.• At least two species of endangered sharks or rays will be successfully bred and released in the

sea. • Greater support for the protection of sharks and rays from authorities, fisheries, and the public

through education and communication.

Christiaan van der Sluis, North Sea Foundation: “Sharks and rays belong in the North Sea. Unfortunately, some shark and ray species are not doing well. A few have even disappeared completely. I think that sharks and rays should not be considered just undesirable bycatch. The presence of these predators here is valuable and important. We can ensure the presence of these special animals in the North Sea by doing a better job of protecting them, restoring their habitats where possible and reintroducing lost species through special breeding projects.”

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PROJECT ORGANISATIONThis project is being executed by the Dutch World Wide Fund for Nature in cooperation with the North Sea Foundation (Stichting de Noordzee), Blue Linked, Dutch Shark Society and the Dutch Angler Association (Sportvisserij Nederland). There is a project team that meet on a regular basis to discuss the progress of the project. The Dutch World Wide Fund for Nature is the project coor-dinator, responsible for the communication to the public, and serves as project leader. The North Sea Foundation is discussion and communication partner. Blue Linked breeds elasmobranchs and will lead the breeding program. The Dutch Angler Association will participate in the tracking system of released sharks. The Dutch Shark Society acts as a communication and media partner, provides visual materials and will document the project.

APPLICANTWorld Wide Fund for Nature the NetherlandsWWF Netherlands works towards a healthy North Sea ecosystem through the recovery and protection of important habitats and species that depend on these habitats, and via the sustainability of the fisheries. WWF Netherlands works on protection through:• policy and legislation;• restoration of shellfish beds, sharks, rays and other important marine animals;• sustainability of fisheries by cooperating with the fisheries; and • by working with manufacturers, retailers, consumers and other important links in the fish

chain.

First release of thornback rays in the Oosterschelde© P

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Niek and a shark© R

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Niels Brevé, Sportvisserij Nederland:“Recreational anglers enjoy underwater life and look after it. For decennia organised recreational anglers have been working on restoring the population of rare fish types, such as salmon and sturgeon and that of various sharks and rays. Sportvisserij Nederland also introduce people to sharks and rays, for instance during the event Sharkatag, when sharks are caught, tagged and released by licensed anglers. The biological data that is gathered during this event is used for the National Shark Action Plan1 and for effective fishery management. This ensures that the fish will be better managed and protected.”

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PARTNERSBlue LinkedThe founder of Blue Linked, Michael Laterveer, has more than 15 years’ experience as a marine biologist in keeping and breeding sharks and rays. As a curator of the Oceanium and the shark tank in Diergaarde Blijdorp, he was one of the founders of the breeding programs for public aquaria (EUAC, FAITAG programs) and he has extensive experience in coordinating the implementation of such programs.

Dutch Angler Association Angling is one of the most important recreational activities in the Netherlands; SVN has 600,000 members. The organization has a royal acknowledgement and has been working for several decades and in diverse ways on the recovery of the characteristic fish stocks. The organization acknowledges the importance of preserving species like sharks and rays for a healthy aquatic ecosystem in the North Sea. A good example, where lobby, research and publicity come together is Sharkatag. A three-day event during which boaters, anglers, politicians and reporters go out to sea together to tag sharks. In cooperation with the North Sea Foundation, they have launched a website, haairog.nl and together with several other organizations have made identification cards and fact sheets that can help fishers to identify shark and ray species.

Dutch Shark SocietyThe Dutch Shark Society is an active intermediate partner between science and people, by supporting and visualizing ocean and elasmobranch research, and developing media initiatives through photography and video within several information platforms. The objective of this NGO is a broad collaboration with governmental and non-governmental institutes, but also with the dive industry, industrial fisheries and recreational anglers.

North Sea Foundation The North Sea Foundation is an independent nature and environmental organisation and is the designated organisation when it concerns protecting and sustainably utilising the North Sea.The foundation focuses on four objectives: protect nature, a clean ocean, sustainable fishing and environmentally friendly energy. In collaboration with others they work toward solving the biggest nature and environmental challenges on the North Sea.

Stichting De Noordzee

Al meer dan 30 jaar geeft Stichting De Noordzee (SDN) de Noordzee een stem, met als doel: een schone en gezonde zee, die invloeden van buiten veerkrachtig opvangt. Een goed functionerend ecosysteem legt daarvoor de basis. SDN zoekt de dialoog en streeft naar oplossingen. SDN is een (inter)nationaal gewaardeerd gesprekspartner, met inhoudelijke kennis. SDN werkt steeds vaker samen met bedrijven uit de sector aan concrete projecten die ten goede komen aan het bedrijf én de Noordzee. Ook richt SDN zich steeds meer op consumenten en het publiek om gedragsverandering te bevorderen en te laten zien hoe mooi onze Noordzee is.

Blue Linked

De oprichter van Blue Linked, Michaël Laterveer, heeft als marien bioloog ruim 15 jaar ervaring met het houden en kweken van haaien en roggen. Als curator van het Oceanium en het haaienbassin in Diergaarde Blijdorp stond hij aan de basis van de oprichting van de kweekprogramma’s voor publieke aquaria (EUAC, FAITAG programma’s) en heeft daarbij een brede ervaring met het uitvoeren van dergelijke programma’s als coördinator.

Sportvisserij Nederland

Sportvissen is één van de grootste vrijetijdsbestedingen van Nederland; Sportvisserij Nederland (SVN) heeft 600.000 leden. De organisatie is koninklijk erkend en werkt sinds decennia op diverse fronten toe naar herstel van de kenmerkende visbestanden. Zij onderkent het behoud van soorten als haaien en roggen voor een gezond ecosysteem in de Noordzee. Een goed voorbeeld, waar lobby, onderzoek en publiciteit bij elkaar komen, is Sharkatag: een 3-daags evenement waarbij schippers, hengelaars, politici en verslaggevers gezamenlijk de zee op gaan om haaien te merken. SDN en SVN lanceerden samen de website haairog.nl en maakten samen met andere organisaties zoekkaarten en factsheets waarmee sportvissers haaien- en roggensoorten kunnen herkennen.

Dutch Shark Society

Dutch Shark Society is een actieve schakel tussen wetenschap en publiek door het steunen van onderzoek, het zichtbaar maken daarvan en het ontwikkelen van media-initiatieven door fotografie en film binnen een informatieplatform. Daarbij streeft deze non-profitorganisatie naar een brede samenwerking met andere instanties en instituten op dit gebied, maar ook met de duikbranche en de professionele en recreatieve visserij.

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Partners



Blue Linked




Dutch Shark Society


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Partners Stichting De Noordzee


Blue Linked




Dutch Shark Society


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Partners



Blue Linked




Dutch Shark Society


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sharks and rays back in the north sea! - dutch shark …€¦ · reproductive biology of sharks is...

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